The invention concerns a gripping chuck for a spool with inner wedge-shaped member which is axially movable against the force of a pressure element and borne by a shaft end and which supports outer shell-like members which constitute gripping jaws that are clampable in the radial direction.
Chucks of this type are known as shown in German Pat. No. Des. 77 10 804. In the known chucks, a diaphram assembly under gas pressure constantly acts on movable wedge-shaped parts in the axial direction, so that the gripping jaws remain constantly tightened in the radial direction. This diaphragm assembly makes the chuck costly, because space must be provided for such assembly and the feeder lines for same. Moreover, it is particularly disadvantageous that the tightening of the gripping jaws by means of the pressure gas can take place only after the spool has been slid onto the chuck. The operating personnel thus have to perform successive specific steps, e.g. sliding on the spool, thereafter introducing the pressure gas and then clamping off the source of the pressure gas.